木材-FRP工程复合材料的发展与展望

综合介绍了木材增强技术的发展现状、研究动态以及木材-FRP工程木质复合材料的发展前景。纤维增强聚合物(FRP)已经在航空、航天、汽车及体育用品等领域得到广泛的应用,而今,FRP作为增强材料应用于木材工业,将形成一门木材、FRP两大材料交叉的新学科,这一新的领域正越来越受到木材工业的重视。     

FRP在建筑结构加固施工中的应用探析

受外部环境及自身特性影响,建筑结构随着使用时间的延长,会逐渐出现变形、破损、老化等诸多问题,这些情况不仅仅影响建筑美观,降低使用性能,严重时还会引发安全事故,终止建筑设施的使用寿命。FRP作为新型材料,在建筑结构维修补强方面有着十分突出的表现。文章针对FRP在建筑结构加固施工有关问题进行探讨,分析了FRP加固技术的基本概念,详细阐述了FRP在建筑结构加固施工领域的诸多应用。     

印花合成增稠剂Lutexal FRP流变性能研究

通过稳态剪切及粘温特性、小幅振荡剪切应力扫描试验,研究了合成增稠剂Lutexal FRP的流变性能,并探讨了金属离子对合成增稠剂Lutexal FRP粘弹性能的影响。结果表明:合成增稠剂Lutexal FRP的流动曲线表现出显著的剪切变稀现象,其表观粘度随温度的升高先下降,然后达到稳定,随后又继续降低。溶液体系以弹性为主,加入金属离子后溶液体系的储能模量和损耗模量降低,损耗角增加,体系的粘性增加,弹性降低。     

玻璃钢技术在化工行业的应用

玻璃钢(FRP)作为复合材料,其质轻坚硬、高机械性、良好的耐腐蚀性。随着科技水平和生产工艺的不断推进,FRP在化工行业得到了日益广泛的应用。文中列举其在化工生产设施、环保处理、石油化工等领域的使用实例,并对发展前景做了展望。     

纤维片材对混凝土结构加固分析和处理

主要介绍FRP复合材料与混凝土结构的加固受力基理、碳纤维加固钢筋混凝土构件受力分析，并例证说明碳纤维加固在实际中的运用。     

纤维增强树脂在工程木质复合材料中的应用

论述纤维增强树脂（FRP）在工程木质复合材料领域中的应用现状,预测其在该领域的研究趋势及发展前景。     

FRP-水泥砂浆抗弯性能的研究

利用三点弯研究了水泥砂浆外贴碳纤维和芳纶纤维片材后的抗弯性能,并对2种纤维进行表面处理,探讨纤维的表面处理对FRP水泥砂浆体系抗弯性能的影响。结果表明,用等离子体分别对碳纤维和芳纶纤维进行表面处理,CFRP和AFRP水泥砂浆的最大断裂载荷都能显著提高,而且构件在受弯过程中没有发生剥离破坏,FRP被拉断,纤维高强的特点得到充分发挥。     

塑料缸──卫浴材料的新秀

由于国际上卫浴设备的需求量增大，SMC（塑料缸）正广泛使用。一方面，可以顺应环保的需求，另一方面则可以大幅度降低劳动成本。同时、同为塑料缸的使用寿命较长，还因制造工艺的改进，其附加值也较高，有可能成为今后卫浴市场的主流产品。按目前使用材料和工艺技术，制造卫浴设备较常使用有FRP（喷布积层）、亚克力、搪瓷、珐琅和SMC等材质，FRP曾介推出的的几年同凡有新鲜感而流行一时，虽然在喷制成型后因表面光滑，色泽稳定等优点备受欢迎，但其制造过程是将树脂和玻璃纤维一层层先后喷制，所以劳动成本较大，也要求制造厂房的面…     

桥梁加固应用中有关混凝土的预应力研究

桥梁是公路建设中的重要内容,并且随着交通量的增加以及负荷的加重,原有的桥梁在承载力上就出现了一些不足,病害出现的情况加重,桥梁在刚度上的性能也远达不到交通的需要,因此,对交通造成了一定的影响。文章就FRP法在桥梁加固中的应用做了一些简要的论述,将FRP法对钢筋混凝土以及预应力的改善加固的优势进行了介绍。     

玻璃钢增强塑料在二氧化氯制备中的应用

在ClO_2制备的生产过程中,由于生产过程所用的原料,产品及副产品都是腐蚀性很强的介质,为了节约投资,很多设备及管道大量使用玻璃钢增强塑料。这些设备是圆柱形结构的,如ClO_2吸收塔、氯酸钠高位槽、贮存槽等,其材料使用PVC/FRP及CPVC/FRP,这代号的意思是:设备或管道本体     

Environmental effects on the bond at the interface between FRP and wood

The advantages of fiber reinforced polymer (FRP), such as high specific strength, resistance against corrosion and formability, have made it a more acceptable alternative to conventional materials regarding repairing and retrofitting of structures. Although investigations in recent years have proved the concern of civil engineers about the environmental effects on the bond between FRP and concrete or masonry (especially moisture and temperature), only few researches have been reported on FRP-wood interfaces. This research investigated the effect of five different environments on the bond at the interface between FRP and wood. A series of pull-out tests were performed on 375 wood specimens bonded with aramid, carbon and glass fibers (wet lay-up) and one type of epoxy resin. Then, these samples were immersed in chemical solutions with pH of 2.5, 7, 10 and 12.5 and substitute sea water for 2, 4, 6, 8, 10 and 13 weeks to estimate bond strength reduction. The effect of dry heat was also investigated. The results of such experimental tests illustrated that an acidic solution had the most effect on the bond between carbon-FRP and wood by 57% reduction. Sea water and fresh water had almost the same effect on the specimens bonded with glass and aramid–FRP (40% reduction), and they had the least influence on the bond between carbon-FRP and wood. Further, alkaline solutions had the most effect on the specimens bonded with glass-FRP. In addition, dry heat did not affect the bond between FRP and wood considerably.     

玄武岩纤维的性能及其制品在土木工程领域的应用

玄武岩纤维是继碳纤维和玻璃纤维后又一种值得关注的无机高性能纤维材料。介绍了玄武岩纤维的化学成分、各项优越特性以及玄武岩纤维制品(短切纱、土工织物以及玄武岩纤维复合筋)在土木工程领域的应用和作用。随着玄武岩纤维性能和产量的提高,玄武岩纤维及其制品将在土木工程领域具有广阔的应用前景。     

Characteristics of fibre‐rich powder and antioxidant activity of pitaya (Hylocereus undatus) peels

The contents of total dietary fibre (TDF), soluble dietary fibre (SDF), insoluble dietary fibre (IDF) and functional properties of fibre‐rich powders (FRP) from pitaya peels with different particle size (FRP80, FRP140 and FRP250) were determined. Results showed that FRP140 had higher TDF (79.37%) and SDF (33.07%) with a balanced ratio of SDF/IDF (1:1.32) and higher water‐holding capacity (54.20 g g^?1), swelling capacity (50.63 mL g^?1), oil‐holding capacity (2.65 g g^?1) and glucose dialysis retardation index (62.83% at 60 min), compared with FRP80 and FRP250. Therefore, physiochemical properties of FRP140 were further investigated. SDF of FRP140 mainly contained rhamnose (4.95%) and galactose (1.98%), with 9.45% galacturonic acid, while IDF dominantly contained xylose (4.76%) and galactose (3.42%), with 18.54% klason lignin. Total phenolic content was 7.75 mg g^?1 and mainly composed of salicylic acid (0.98 mg g^?1) and protocatechuic acid (0.45 mg g^?1). Furthermore, FRP140 showed significant reducing power, DPPH‐scavenging activity and nitrite‐scavenging ability.     

纤维复合材料在土木建筑工程中的应用

针对土木和建筑工程的发展趋势,探讨纤维复合材料在土木和建筑工程中应用的优势。介绍了国内外纤维复合材料在土木和建筑工程中应用的进展。     

Genetic relationships of lactose and freezing point with minerals and coagulation traits predicted from milk mid-infrared spectra in Holstein cows

The aim of the present study was to assess the relationships of lactose percentage (LP), lactose yield (LY), and freezing point (FRP) with minerals and coagulation properties predicted from mid-infrared spectra in bovine milk. To achieve this purpose, we analyzed 54,263 test-day records of 4,297 Holstein cows to compute (co)variance components with a linear repeatability animal model. Parity, stage of lactation, season of calving, and herd-test-date were included as fixed effects in the model, and additive genetic animal, within- and across-lactation permanent environment, and residual were included as random effects. Lactose percentage was more heritable (0.405 ± 0.027) than LY (0.121 ± 0.021) and FRP (0.132 ± 0.014). Heritabilities (± standard error) of predicted milk minerals varied from 0.375 ± 0.027 for Na to 0.531 ± 0.028 for P, and those of milk coagulation properties ranged from 0.348 ± 0.052 for rennet coagulation time to 0.430 ± 0.026 for curd firming time. Lactose percentage showed favorable (negative) genetic correlations with milk somatic cell score (SCS) and FRP, and it was almost uncorrelated with casein-related minerals (Ca and P) and coagulation properties. Moreover, LP was strongly correlated with Na (−0.783 ± 0.022), a mineral known to increase in the presence of intramammary infection (IMI) and high somatic cell count. Indeed, Na is the main osmotic replacer of lactose in mastitic milk when the blood–milk barrier is altered during IMI. Being strongly associated with milk yield, LY did not favorably correlate with coagulation properties, likely because of the negative correlation of this trait with protein and casein percentages. Milk FRP presented moderate and null genetic associations with Na and SCS, respectively. Results of the present study suggest that the moderate heritability of LP and its genetic correlations with IMI-related traits (Na and SCS) could be exploited for genetic selection against mastitis. Moreover, selection for LP would not impair milk coagulation characteristics or Ca and P content, which are important for cheesemaking.     

可生物降解聚乳酸非织造布

本文论述了采用熔融纺丝法纺制聚乳酸纤维和纺粘法非织造布的生产工艺 ,以及聚乳酸短纤维的干法成网非织造布生产技术。聚乳酸非织造布是一种以可再生资源玉米等为原料的新型材料 ,具有良好的可生物降解性、加工性和力学性能 ,可应用于医疗卫生、农业、园艺、生活用品等 ,用途广泛。     

Porosity and barrier properties of polyethylene meltblown nonwovens

There are several areas in which textiles have been highly desirable due to their specific and high performance for many industries and sectors including in civil engineering, automobile, medicine, filtration, and electronics. Polymer used has a significant effect on the properties of meltblown nonwovens. Polypropylene being the most commonly used polymer, very limited data have been reported on the polyethylene meltblown nonwovens which are desired due to their unique processing and performance advantages. In this study, we have investigated the effects of process variables, die temperature, air pressure, and die-to-collector distance on some characteristics of polyethylene meltblown nonwovens such as pore size, air permeability, hydrostatic head, and SEM analysis. It was observed that the variables have significant effects on the produced nonwovens, and many of the properties are comparable to those obtained with that of polypropylene meltblown webs.     

ER/MR智能材料及其在土木工程结构振动控制中的应用

综述了电流变体/磁流变体(ER/MR)智能材料的基本性能,ER/MR智能减振驱动器的工作原理、力学模型,介绍了其在我国土木工程结构振动控制中的应用,提出了未来的研究方向.     

Characterization of a fibre-rich powder prepared by liquefaction of unripe banana flour

The development of nutraceutical ingredients is of current interest for the food industry. A fibre-rich powder (FRP) was prepared by liquefaction of raw banana flour (RBF) and its chemical composition, water- and oil-holding capacity, and antioxidant capacity were evaluated. Total dietary fibre (TDF) was higher in FRP than in the RBF, but the total starch (TS), potentially available starch (AS) and resistant starch (RS) contents were lower in the processed product, since the liquefaction process involves granular disruption and starch hydrolysis, resulting in reduced TS and AS and increased TDF. The reduced RS content is also explained by the loss of granular integrity, which is the main factor responsible for the indigestibility of native banana starch. Total indigestible fraction content of FRP was relatively high, the soluble fraction being lower than the insoluble portion. A very fast reduction of DPPH was observed in the presence of FRP, indicating that polyphenols in this preparation efficiently quench free radicals. Tested at various temperatures, the FRP and RBF exhibited similar water-and oil-holding capacities. The main difference was observed in water-holding capacity at 80 °C, where FRP was less efficient than the raw material, a fact associated with starch gelatinization in RBF treated at that temperature. FRP might be a potential ingredient for development of products with high TDF and indigestible fraction contents, as well as important antioxidant capacity.